Hotspot volcanoes

An incredible “lost world” of underwater volcanoes discovered at the bottom of the ocean

Hidden beneath the waves off the east coast of Australia, scientists have discovered a “lost world” of epic volcanic peaks buried beneath the Tasman Sea, never before seen by human eyes.

This chain of volcanic seamounts – underwater mountains formed by ancient, extinct volcanoes – rise about 3 kilometers (1.9 miles) above the ocean floor. Despite its immense height, it has never been detected before, since even the highest peaks are hidden 2 km (1.2 miles) below the surface of the South Pacific.

“Our multibeam mapping revealed for the first time in vivid detail a chain of volcanic seamounts rising from an abyssal plain about 5,000 meters (16,400 feet) deep,” says marine geoscientist Tara Martin. from the Australian CSIRO.

“It is a very diverse landscape and will undoubtedly be a biological hotspot that is home to a dazzling array of marine life.”

The researchers say the volcanic terrain varies in size and shape, including both sharp peaks and broad plateaus punctuated by smaller conical hills.

The discovery, made aboard the research vessel CSIRO Investigatorhappened during a trip led by scientists from the Australian National University.

The team were examining the relationship between nutrient levels and phytoplankton behavior in the East Australian Current when their seafloor mapping detected the dramatic, unexplored contours produced in another time in history.

“We’re pretty sure these seamounts were related to the breakup of Australia and Antarctica. That was about 30 million years ago,” Martin told ABC News.

“As Australia, Antarctica and Tasmania all split apart, a large hotspot entered beneath the earth’s crust, created these volcanoes, and then helped the earth’s crust break up so all of these areas could begin to separate.”

Future research is already planned to survey the terrain and its marine life later in the Australian summer, but researchers already think these volcanic valleys could serve as something of a navigational hub for creatures that dwell in the depths.


“These seamounts may act as an important signpost on an underwater migratory highway for humpback whales that we have seen moving from their winter breeding grounds to their summer feeding grounds,” the report said. one of the team, zoologist and bird researcher Eric Woehler from the University of Tasmania. A declaration.

“We expect these seamounts to be a year-round biological hotspot, and the summer visit will give us another opportunity to uncover the mysteries of the marine life they harbor.”

In addition to humpback whales, researchers have seen an increase in ocean productivity above seamounts, including spikes in phytoplankton activity, as well as many sightings of other marine life, such as a giant pod of 60-80 pilot whales and seabirds (four species of albatrosses each). and petrels).

051 volcanic seamounts 3Humpback Whale (Eric Woehler)

Given how new this discovery is, we don’t yet fully understand how this lost world and its ocean inhabitants interact.

But there’s no doubt that we’ve discovered a vibrant and diverse ecosystem here – a handy place to stop for food or orientation, whether you’ve got scales, feathers or just bits of plankton.

051 volcanic seamounts 3Black-browed Albatross (Eric Woehler)

“These seamounts are changing the oceanography in these areas,” Woehler told ABC News.

“They change the way the water flows around them. They change the dynamics of the system.”